Create support case to enable MFA

I received an email to enable MFA. I was asked to do three things.

1. Change root password. I have done this.
2. Enable MFA. I have done this
3. Create Support Case to confirm completion of the steps above. However, I do not know hot to do this.

The complete tekst of step 3 is: --- quote --- [IMPORTANT] You must create a new Support Case to confirm completion of the steps above in order to secure your account. You can create a new one by going here: https://console.aws.amazon.com/support/home?#/ --- unquote --- When I go to the web page I can create a Support Case, but I have to choose from a number of categories and sub-categories, and I have no idea how to proceed.

Can anyone help?

Thanks in advance.